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USB: musb: Enable the maximum supported burst mode for DMA
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Setting MUSB Burst Mode 3 automatically enables support for
lower burst modes (BURST4, BURST8, BURST16 or bursts of unspecified
length). There is no need to set these burst modes based on the
packet size. Also enable the burst mode for both mode1 and mode0.

This is a fix for buggy hardware - having the lower burst modes
enabled can potentially cause lockups of the DMA engine used in
OMAP2/3/4 chips.

Signed-off-by: Hema HK <hemahk@ti.com>
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Acked-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Hema HK authored and Greg Kroah-Hartman committed Jun 30, 2010
1 parent f2263db commit c0f1f8e
Showing 1 changed file with 2 additions and 11 deletions.
13 changes: 2 additions & 11 deletions drivers/usb/musb/musbhsdma.c
Original file line number Diff line number Diff line change
Expand Up @@ -132,18 +132,9 @@ static void configure_channel(struct dma_channel *channel,
if (mode) {
csr |= 1 << MUSB_HSDMA_MODE1_SHIFT;
BUG_ON(len < packet_sz);

if (packet_sz >= 64) {
csr |= MUSB_HSDMA_BURSTMODE_INCR16
<< MUSB_HSDMA_BURSTMODE_SHIFT;
} else if (packet_sz >= 32) {
csr |= MUSB_HSDMA_BURSTMODE_INCR8
<< MUSB_HSDMA_BURSTMODE_SHIFT;
} else if (packet_sz >= 16) {
csr |= MUSB_HSDMA_BURSTMODE_INCR4
<< MUSB_HSDMA_BURSTMODE_SHIFT;
}
}
csr |= MUSB_HSDMA_BURSTMODE_INCR16
<< MUSB_HSDMA_BURSTMODE_SHIFT;

csr |= (musb_channel->epnum << MUSB_HSDMA_ENDPOINT_SHIFT)
| (1 << MUSB_HSDMA_ENABLE_SHIFT)
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